Joint for use in drop hammers



P" 7, 1953 R. E. CERNEA JOINT FOR USE IN DROP HAMMERS Filed Dec. 2, 1949 INVENTOR- ROLAND E. 'CERNEA *M ATTORNEYS.

FIG. 4.

Patented Apr. 7, 1953 STATES JQINT FOR USE IN DROP HAMMERS Roland E.- Gemea, h ladelphia, Pa. 'ApplicationDecemberZ, 1949, Serial No. 130,725

a. Claim.

y r 1. "Ibis invention relates to an improvement in amp h mmers. and, while adaptable to, drop hammers generally, is more particularly adaptable to steam drop hammers intended for heavy work.

More specifically, this invention relates to a novel design or construction for connecting the piston rod and ram in a drop hammer.

Drop hammers of various form and design and their function are well known; and it is equally well known that in their operation, and especially in the case of steam actuated hammers adapted for heavy work, the rod affording connections between the power source and the ram of the hammer is subjected to frequent breakage causing loss of work time and considerable expense.

Breakage of the rod in prior designs usually occurs at about or somewhat above the juncture of the rod and ram and is believed to result from fatigue of the metal of the rod caused by vibration set up by whipping of the rod brought about by, among other things, the rapid movement and impacts of the ram, unsymmetrical distribution of metal in the die cavities and slight inaccuracies in the guide.

Various efforts have been made and various designs have been produced with a view to avoiding breakage of the rod. However, none have heretofore effectively solved the problem especially in the case of steam hammers adapted for heavy work.

Now in accordance with this invention, there is provided a novel form of connection between the rod and the ram which effectively compensates for, or negatives the breaking effect of, the cause of rod breakage; and which at the same time is simple and inexpensive to produce and install.

Having now indicated in a general way the nature and purpose of this invention, I will proceed, with respect to the accompanying drawing, to describe in detail a preferred embodiment thereof, from which this invention in its broad and more specific aspects will be made apparent.

In the drawings:

Figure 1 is a view in elevation of a rod and ram assembly embodying a preferred embodiment of this invention.

Figure 2 is a cross sectional view on line 2-2 of Figure 1.

Figures 3,4 and 5 are respectively perspective views showing, in detail, elements of the assembly shown in Figure 1. V

A drop hammer structure in full detail has not been illust ated and will not be descr bed sires such is well known and th apnlie. Mon 9!; the assembly embodying this invention to drop b 4 1 were .of various typ s and des n-will be ap I.

In the several es of the drawing, A sates a piston connected for ope ation oi a are B, carrying a die 0, through a rod D.

The ram B is provided with a central cylindrical bore 2 extending from its upper end to adjacent its lower end and with a cylindrical bore 3 extending from its lower end and opening into the bore 2 in axial alignment therewith. The bore 3 is of smaller diameter than the bore 2 so that an annular shoulder or ledge 4 is formed at their juncture.

In the bore 2 is inserted, with a tight fit, a sleeve or bushing 5.

The sleeve 5, shown in Figure 3, is exteriorly cylindrical to fit the bores 2 and is split, as at 6, to facilitate its insertion into the bore 2. The sleeve 5 is tapered internally and is positioned in here 2 with its lower end resting on the annular shoulder 4, the interior taper being such that the opening in the sleeve at its lower end is clear of the edge of the shoulder 4.

Within the sleeve 5 is inserted a solid plug I, shown in Figure 4, externally tapered to fit the tapered interior of the sleeve 5. The plug 1 is split as at 8, and has a spherical socket 9 formed in its upper end opening on a slight taper as shown at H). a

The upper end of rod D is connected to the piston A in any desired usual manner and is tapered toward its lower end which is of spherical form as shown at H, Figure 5. The diameter of the spherical or ball end of the rod is not greater and preferably is about the same as the maximu cross sectional dimension of the rod.

Referring now more particularly to Figure 1, the assembly is accomplished by first inserting the sleeve 5 in the bore 2 on the ram. Then the spherical or ball end of the rod is engaged in the socket 9 in the plug 1, the socket being sized to fit the ball, engagement being accomplished by bringing the two halves of the plug together about the ball. The plug 1 is then inserted in the sleeve 5.

As will now be apparent, when the ram is operated, the force incident to the die striking the work will be absorbed over the entire bearing surface of the plug 1 with the interior of sleeve 5 and hence transmitted to the rod with minimum effect on the rod. And it will be noted that the plug I may, to insure full bearing with the sleeve,

-' move downwardly on the sleeve into the bore 3.

3 since its lower end is clear of the edge of shoulder 4 upon which the sleeve is supported.

Further, in the reciprocation of the ram and when the die strikes the work, if there be inaccuracy in the guides or irregularities in the work, resultant displacement of the ram will not cause the rod to whip since the ball and socket connections between the ram and rod will permit the ram to rock without effect upon the rod.

It will be appreciated that various modifications in detail may be made in the embodiment of the invention described above, for illustrative purposes, without departing from the scope of the appended claim.

What is claimed is:

Means to connect a drop hammer ram and a piston for the operation of said ram which comprises an operating rod fixedly secured to the piston and having a spherical end remote'from the piston, the surface of said spherical end being joined to the surface of the remainder of the rod by a smoothly developed curved surface, said rod tapering from its upper end to the point where it joins said spherical end, an internally tapered split bushing positioned within a bore in said ram and resting on a shoulder in said bore,

a tapered plug split throughout its length on a plane passing through its axis and having a spherical socket formed in one end, said plug being positioned in said bushing and engaging the spherical end of said rod, the diameter of the lower end of the plug being smaller than the diameter of the portion of said bore extending downwardly from said shoulder.

ROLAND E. CERNEA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

